Aldehyde antistain baths for developed color photographic material



Patented Aug. 15,1950

UNITE-D sra'r ss PATENT OFFICE 2,518,686 x lemmas ANTI'STAIN BATHS FORDEVEL- OPED COLOR PHOTOGRAPHIIC MATERIAL h Harold C. Harsh and JamesBates, Bingham i ton, N, ..Y.', assignors to General Aniline. &Fil'mC'orporation', New York, N. Y., a corpora- 'tion of Delaware .NoDrawing.

This invention relatestojphotographic anti stain baths, to' antistainbaths employed in multi-color photography, and especially to nonstainingbaths for the washing of multi-color photographic material following thefixing treatment.

It is known that in, the'processing of multicolor reversible film andmulti-color reversible white opaque the exposed film or exposed whiteopaque, is first developedwi'th a normal black and white developertoproduce a negative image. After development, the black and whitenegative material, without being fixed, is exposed to generalillumination, followed by asecond development with a color-formingdeveloper. During the first and second development the silver-halides inall the layers are reduced to metallic silver. After the seconddevelopment, the material is cleared in running watenhardened in anaqueous solution consisting of either chrome or potassium alum, and thenwashed in running: water. After the latter treatment, thesilver present.in

all the layers formed during thefirst and second development isconverted into a, saltby anyot and bleach solutions be removed,otherwise stains will be formed during-the-drying operation,

which are particularly noticeable in.;the white.

area. In order to prevent this staining, an extended final washing timein running water of from fifteen minutes to two hours hasbeen proposed.Even if this proposalbe adopted, stains are nevertheless formed aftervthe drying operation, It is believed that the staining results from theoxidation of traces of the color developer retained in the layers of thematerial'following color-forming development, which then react with theunused color-former.

An object of the present invention is to eliminate excessive washingtime of color developed mul ti-color photographic material whilepreventing the formation of stain.

A further object of the invention is a final Application November 8,1945, a Serial No. 627,532

7 '4 Claims. (Cl. 88)

, 2 rinse' bath which clears undesirable matter from a multi-colorphotographic material in a short time while avoiding staining.

Other objects and features ofthe invention will become more apparent asthe description proceeds.

Wehave found that the above objects are ac-- complished by employing, asa final rinse bath, an aqueous solution containing a small quantity ofan aliphatic aldehyde, such as formaldehyde, paraformaldehyde(trioxymethylene), acetaldehyde (p'araldehyde), aldol, crotonaldehyde,propionaldehyde, and the like. makes it possible to considerably reducethe final washing time. The, concentration of the aliphatic aldehyderequired may vary considerably. For instance, as little as 1 cc. of analiphatic aldehyde per liter of water has been found to eliminate stainfor the most part, but as much as cc. per liter. may be used if onewishes to take the greatest precaution to ensure freedom from stain.

Amounts higher than 20 cc. per liter give little improvement in stainprevention from a practical standpoint, and accordingly, concentrationsranging from between 10 cc. and 20 cc. per liter are most desirable.

v The photographic multi-layer materials, which may beprocessed with theanti-stain bath of the present invention, are color reversible film,color negative film, color reversiblewhite printing material coated onan opaque base, and color positive" printing material coated on paper,irrespective of Whether the dyestuff images are produced withcolor-formers present in the emulsion, or by a selective second exposurefollowed by color development.

The color reversible film consists of an integral tripack emulsioncoated on the usual clear cellulose acetate or nitrate film base. Eachof the emulsions are sensitized to one of the primary colors of light;namely, blue, green, and red. The top layer is blue sensitive. A filterlayer, yellow in color and blue absorbing, lies under the top layer.Below this filter layer, lies a green sensitive emulsion layer, andbelow this is a red sensitive'emulsion layer. Each of the threesilverhalide emulsion layers contain dye-forming compounds which uniteduring the development of a silver image in an aromatic amine developingThis discovery agent to form a dye with the oxidation product of thedeveloping agent, or may be free from colorformers in which case thefilm is processed with the color-formers in the color developers by theselective second exposure and color development method as described inUnited States Patents 1,897,866; 1,900,870; 1,928,709 and 1,980,941. Thecolor negative film is made up in the same manner as the colorreversible film with the exception that it may contain a layer of cleargelatin between the red, sensitive layer and the green sensitive layer.The color reversible white opaque material is prepared in the samemanner as color reversible film and the color negative film with theexception that the base consists of an opaque white film. The colorpaper is also constructed in the same manner as the color reversiblefilm and the color negative with the exception that the emulsion iscoated on a baryta coated paper base.

As silver is formed during development, it must be removed after colordevelopment by treatment in a bleach, followed by treatment in a bath ofsodium thiosulfate, according to usual practice. A yellow dye is formedin the blue sensitive emulsion; a magenta dye is formed in the greensensitive emulsion; and a cyan dye is formed in the red sensitiveemulsion. Combinations of these three printing primaries will produceall of the other colors in the finished film or print. Suitable methodsfor the preparation of photographic multilayer materials have beendescribed in the literature relating to color photography, and are,therefore, not described here.

The following examples describe in detail methods for accomplishing theabove objects, but it is to be understood that they are inserted merelyfor purposes of illustration and are not to be construed as limiting thescope of the invention.

Example I A 4" x 5" full color transparency sheet of color film wasprinted by contact on two 4"" x 5 sheets of color reversible Whiteopaque film.

The two sheets of 4" x 5" color reversible white opaque film were firstdeveloped for twelve minutes at 68 F. in a developer of the followingcomposition:

Water to make up 1 liter.

Short stopped for 3 minutes at 68 11, in a 5% aqueous solution Of sodiumbisulfite.

,Washed for 2 minutes in running water at. 68 F.

Color developed for 15. minutes at 681 R, in a developer of thefollowing composition:-

Water to make up 1 liter.

Rinsed for 4 minutes in running water at 68 F.

Hardened for 5 minutes in a 3% aqueous solution of potassium chrome alumWashed for 5 minutes. in runnin Water at '4 68 F. The washed materialwas then treated with a bleach bath of the following composition:

Water to make up 1 liter.

Washed for 5 minutes. at. 68. F., and then fixed for 5 minutes in asolution of the following composition:

Grams Hypo 200 Borax 10 Water to make up 1 liter.

After fixing, the material was washed for 10 minutes in running water at68 F.

After the final wash, one print was allowed to dry while the other wasrinsed for two minutes in a solution containing 10 cc. of formalin perliter of water and then allowed to dry. At this point the printsappeared identical. After normal drying, the print rinsed in theformalin solution showed brighter colors and more brilliant highlightsthan the print given only a water wash for 15-20 minutes.

When the drying was carried out under conditions of high humidity sothat. the drying time was extended for several hours, the water rinsedprint showed even greater highlight stains while the print rinsed; informalin solution did not change.

Example II Example I was repeated with the exception that the coloredmaterial employed was a color paper and the final rinse contained ZO cc.of acetaldehyde instead of formalin. The color print washed in watershowed objectionable stains after drying while the print treated withthe solution containing ac'etal'dehyde was clear and unstained.

Example III plain water shows marked staining upon drying of saidmaterial. This staining occurs especially under slow drying conditionsand is probably" due to the coupling of the slow oxidation product ofthe color developer with a residual color-coupler present. in one ormore layers.

In place of aliphatic al'd'ehydes referred to above, organic. hardeningagents such as the hydroxy' aldehydes. described in Sheppard and Houch,United States Patent 2,059,817, and thedialkyl diketones described. inStand and Briggs, United: States Patent 2,663,351, mayalso be em-Dloyed.

The abovespecifi'c examples are to be regarded as merely illustrativeofi'the-invention, and not inany sense restrictive. It. willbe obviousto any one skilled: in the. art that many modificationssuchassubstitntingequivalent material and varythe oportions of materialsused are within the spirit and scopeot the invention asdefined' in theappended claims.

We claim:

1. In a process of producing color photographic images selected from theclass consisting of indophenol and azomethine dyes in a multilayer colorfilm by exposing the film, color-forming developing the same, bleaching,fixing and washing, the improvement which comprises avoiding theformation of stain, after the bleaching, fixing, and washing operation,by rinsing the said film with an aqueous solution consisting of waterand a carbonyl compound selected from the class con.- sisting ofaliphatic aldehydes and. di-ketones.

2. In a process of producing color photographic images selected from theclass consisting of indophenol and azomethine dyes in a multilayer colorfilm by exposing the film,.colorforming develop ing the same, bleaching,fixing and washing, the improvement which comprises avoiding theformation of stain, after the bleaching, fixing, and washing operation,by rinsing the film with an aqueous solution consisting of water andformaldehyde.

3. In a process of producing color photographic images selected from theclass consisting of indophenol and azomethine dyes in a multilayer colorfilm by exposing the film, color-forming developing the same, bleaching,fixing and washing, the improvement which comprises avoiding theformation of stain, after the bleaching, fixing, and washing operation,by rinsing the film with an .aqueous solution consisting of water andacetaldehyde.

4. In a process of producing color photographic images selected from theclass consisting of indophenol and azomethine dyes in a multilayer colorfilm by exposing the film, color-forming developing the same, bleaching,fixing and washing, the

6 improvement which comprises avoiding the formation of stain, after thebleaching, fixing, and washing operation, by rinsing the film with anaqueous solution consisting of water and crotonaldehyde.

HAROLD C. HARSH.

JAMES E. BATES.

REFHERENCES CITED The following references are of record, in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Neblette, The Glazing of Prints,Camera Craft, vol. 32, March 1925, pages 116, 118 and 120 (Copy inLibrary of Congress; Photostat in 95-8$ A.)

Ankersmit, "Rapid Drying of Plates and Films, Eastman Kodak 00., MonthlyAbstract Bulletin, vol. XIV, No. 5, May 1928, page 239. (Copy inScientific Library (Abstract of Photofreund, vol. 8, Feb. 20, 1928,pages -1).)

Case, Drying Prints and Negatives, Amateur Photographer, 68, October 23,1929, page 375. (Copy in U. S. National Museum; Photostat in -88 A.)

1. IN A PROCESS OF PRODUCING COLOR PHOTOGRAPHIC IMAGES SELECTED FROM THECLASS CONSISTING OF INDOPHENOL AND AZOMETHINE DYES IN A MULTILAYER COLORFILM BY EXPOSING THE FILM, COLOR-FORMING DEVELOPING THE SAME, BLEACHING,FIXING AND WASHING, THE IMPROVEMENT WHICH COMPRISES AVOIDING THEFORMATION OF STAIN, AFTER THE BLEACHING, FIXING, AND WASHING OPERATION,BY RINSING THE SAID FILM WITH AN AQUEOUS SOLUTION CONSISTING OF WATERAND A CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF ALIPHATICALDEHYDES AND DI-KETONES.